Future wireless communication systems show different trends.
So called reconfigurable front ends able to support different
communication standards along the same signal path more and more
appear into the scope of interest. TU Berlin works at system architecture
studies and RF- circuit design of such multi standard systems
for 4G wireless systems.
Integration density, power consumption and costs are the key
challenges of this research. Another research field are wireless
ad hoc networks at 24 GHz. Here we focus on ultra low power systems
which are usually narrow band with low data rates. Because of
the absence of rechargeable power supplies power efficiency is
the most important aspect and very power efficient system architectures
and RFICs are the mainstream of this research. Such systems are
realized as sensor or so called pico cell networks where communication
nodes should be almost invisible. Therefore, frequency has to
be chosen as high as possible and 24 GHz has to be seen as starting
value. For this type of application, new system concepts are evaluated
and demonstrated. E. g., to overcome the problems with strongly
limited battery power, the whole system nodes have to sleep most
of their live time and have to be enabled by a wake up call. The
investigation of wake up circuits with very low stand by power
consumption is in the scope of this project, too.
A third topic is the development of RF function blocks for 60
GHz WLAN systems. In this field we are working on fundamental
investigations of RFICs like LNAs, PAs, VCOs, frequency conversion
circuits, modulators and RF front-end architectures. |
